Code.org Express 3

In computer science, variables

• are always represented by the letter x

• are an unknown that you are trying to solve for

• are a placeholder for information that can change in the program

• cannot be used with conditionals and functions.

Variable names

• should always be numbers

• will never contain numbers, only letters

• will be similar to the names of conditionals, containing only the words true or false

• should make sense based on what the variable represents

Variables can be used

• only once in a program

• only once and must be used within conditionals

• only in "for loops"

• can be used multiple times in a program

A "constant" variable

• sets the value of the variable once at the beginning of the program and never changes

• sets the value of the variable only at the end of the program

• is never useful when writing an algorithm

• is an advanced use of variables

All of the following are benefits of using variables EXCEPT

• Using a constant allows you to change a variable in ONE place even though you have used the variable in MULTIPLE places

• Makes code easier to read

• Makes code easier to read and debug

• variables make using code less flexible and not able to change.

When we initialize a variable, we

• define the set of commands that the variable will run when called

• give the variable a name and an initial value

• always set the variable to the starting value of 0

• give it initials, like a nickname

to write code, or to write instructions for a computer

• code

• event

• program

An action that causes something to happen

• code

• event

• program

An algorithm that has been coded into something that can be run by a machine

• code

• event

• program

A list of steps to finish a task

• algrorithm

• bug

• debugging

• sequencing